}
	i := idnaIndex[c0]
	if c0 < 0xE0 { // 2-byte UTF-8
		return t.lookupValue(uint32(i), s[1])
	}
	i = idnaIndex[uint32(i)<<6+uint32(s[1])]
	if c0 < 0xF0 { // 3-byte UTF-8
		return t.lookupValue(uint32(i), s[2])
	}
	i = idnaIndex[uint32(i)<<6+uint32(s[2])]
	if c0 < 0xF8 { // 4-byte UTF-8
		return t.lookupValue(uint32(i), s[3])
	}
	return 0
}

type onlyValuesCtx struct {
	context.Context
	lookupValues context.Context
}

var _ context.Context = (*onlyValuesCtx)(nil)

// Value performs a lookup if the original context hasn't expired.
func (ovc *onlyValuesCtx) Value(key any) any {
	select {
	case <-ovc.lookupValues.Done():
		return nil
	default:
		return ovc.lookupValues.Value(key)
	}
}